The IBM mainframe is 50 years old this week. The machine now celebrating its half century wasn't the first business computer of course — that was the LEO, which was built for the UK catering and cakes company Lyons way back in 1951. But unlike the LEOs, which were finally decommissioned in the early 1980s, the mainframe powers on. According to one recent survey, more than half of enterprise applications still call on a mainframe to complete their transactions, and CIOs say their mainframe workloads continue to increase.

There are plenty of reasons for that — the mainframe has turned out to be a solid and extremely reliable piece of enterprise computing infrastructure. Mainframes still sit at the back of most essential business systems, power ATM transactions, and as much as 80 percent of corporate data still sits on big iron. Few organisations wish to go through the pain of moving those essential systems and data away from mainframes unless they absolutely have to.

In the age of the cloud, some might consider the mainframe to be a dinosaur — but it's a dinosaur that you disturb at your peril.

Indeed, it's the humans, not the technology, that have proved to be the bigger problem for mainframe-using companies; the baby boomer engineers who programmed the mainframes are retiring and those skills are proving hard to replace.

It's fair to say that the arrival of the mainframe was also the birth of the enterprise tech industry as we know it. The widespread adoption of computing power was first used to automate accounting and then went on to create new ways of doing business.

A computer that took up most of a room was undoubtedly an impressive sight, but since then our computers have got far smaller while their impact on business and society has become far greater. It's unlikely that those early engineers ever imagined the vast computing power that we harness today as part of our everyday lives without even thinking about it.

Over the next 50 years, that processing power will be even less visible and even more powerful. The era of big iron is already giving way to the era of all-but invisible, pervasive, ambient computing, (the underlying processing power provided by datacentre that are out of sight and out of mind).

We're already seeing the start of that in the steps towards the internet of things and the gradual improvements in digital personal assistants — or IBM's own Watson cognitive computing project. All point to a future where computing is embedded in nearly everything — and probably even in ourselves.

None of this is certain of course, or without its own new problems, even if we're not overwhelmed by grey goo, exterminated by an unhinged AI or succumb to the singularity. Working out how to deal with the challenges created by technology, from automation-related unemployment to economic inequality, will be vitally important.

And so what will be the long-term impact of the mainframe era? It's tempting to echo the response of Chinese premier Zhou Enlai when asked about the impact of the French Revolution: it's way too early to tell.

ZDNet's Monday Morning Opener is our opening salvo for the week in tech. As a global site, this editorial publishes on Monday at 8am AEST in Sydney, Australia, which is 6pm Eastern Time on Sunday in the US. It is written by a member of ZDNet's global editorial board, which is comprised of our lead editors across Asia, Australia, Europe, and the US.